By preaching an old-fashioned message of racial harmony in his bid for the Democratic presidential nomination, Arkansas Gov. Bill Clinton is trying to knit back together the traditional Democratic coalition of blacks and blue-collar whites that was ripped apart more than a decade ago with the election of Ronald Reagan.

In speaking to both black and working-class white audiences in the past two days, Clinton has delivered the same message: Racial hatred only serves to thwart efforts to improve the economic lives of all Americans.

That was the word he brought on Friday to a revival-style political rally of black churchgoers at the Pleasant Grove Baptist Church in Detroit. "If you continue to be divided by race, you will continue to be poor and ignorant," he said. "It will impoverish your spirit and your pocketbook."

And it was the message he left with a predominantly white audience of so-called Reagan Democrats on Thursday in the Detroit suburb of Warren, Mich. "The problems (of the nation) are not racial in nature," he said. "This is a crisis of economics and of values. It has nothing to do with race."

In both places, he also accused President Bush and the Republicans of sowing the seeds of racial disharmony in order to retain the support of the Reagan Democrats and retain control of the White House.

The reaction of Clinton's two audiences to his appeal for racial harmony was overwhelmingly positive, but a better measure of his strategy will come in the primaries Tuesday in Illinois and Michigan, where Clinton needs the support of both blacks and working-class whites in order to counter former Massachusetts Sen. Paul E. Tsongas' popularity among upscale, suburban Democrats.

Although Clinton used a similar strategy in primaries in the South, this is the first test in the industrial states of the North of his effort to bridge racial differences.

In the Southern primaries, Clinton had a stronger appeal among white working-class voters because he is a white Southerner. In the North, where there is no regional affinity, Clinton clearly has stronger support among blacks than he does among working-class white voters.

In Michigan, where race has often been a divisive issue in presidential politics, blue-collar workers also are more likely to be suspicious of Clinton because he comes from a right-to-work state and because he supports a free-trade agreement with Mexico, which auto workers fear will move more American manufacturing jobs into Mexico.

As a result, Clinton's decision to emphasize racial issues in Illinois and Michigan is unusual. It is also evidence of his growing confidence that he will win the Illinois and Michigan primaries and go on to capture the Democratic nomination.

Although he is not yet predicting victory, Clinton's aides said his message of racial harmony will be part of "a general election strategy" he hopes will enable him to win the support of Reagan Democrats who voted for Bush in 1988.

As Clinton told his Warren audience: "I'm trying to give you a new Democratic Party based on old values that will make you want to come home to the Democratic Party. Somebody's got to come back to Reagan Democratic areas and say: ,'Look, I'll give you your values back. . . . I'll help you build the middle class back,' but you have got to say, 'O.K., let's do it with everybody in the country.' "

Clinton, speaking in a county that went 63% for Bush in 1988, was cheered when he told the Warren voters that their resentment toward minorities would disappear if they had better economic opportunities. As President, he promised to provide those opportunities. "It's amazing how, when your life works, you don't feel those resentments," he said.

It is not unusual for a candidate to talk about racial issues in front of a black audience. But Clinton's message to the Baptist church crowd was somewhat out of the ordinary because it emphasized a need for blacks to help themselves and did not emphasize social injustices suffered by blacks.